前言
本章的内容主要是针对于消费者来说的,
在上章的内容都是针对于生产者与broker的两点来讲的:
总结回顾下:
1、ConfirmListener监听(消息确认:需要开启 channel.confirmSelect();消息投递模式)
2、addReturnListener监听(失败返回信息:不需要开启什么,不过需要写逻辑代码)
在这个章节中我们重点了解消费者与broker之间的一个交流
消费端限流
这个可以有经典案例的,比如:
某某的一个限时秒杀,在限时秒杀中一个的数据量是多少呢?
在那个的一瞬间的数据量可以达到几万的数据,一个订单就要给消息服务发送多少的数据,那么在两个服务之间如果没有消息中间价的话,绝对就ggl。所以我们讲的第一个策略就是限流,不管你们来的数据有多少,方正我一次只接纳规定数量。
RabbitMQ提供了一种 qos(服务质量保证) 功能,即在非自动确认消息的前提下,如果一定数目的消息(通过基于Consumer或者Channel设置Qos的值)未被确认前,不进行消费新的消息
MyConsumer
package com.liwangwang.rabbitmq01.limit;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import java.io.IOException;
public class MyConsumer extends DefaultConsumer {
private Channel channel ;
public MyConsumer(Channel channel) {
super(channel);
this.channel = channel;
}
@Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
System.err.println("-----------consume message----------");
System.err.println("consumerTag: " + consumerTag);
System.err.println("envelope: " + envelope);
System.err.println("properties: " + properties);
System.err.println("body: " + new String(body));
channel.basicAck(envelope.getDeliveryTag(), false);
}
}
Consumer
package com.liwangwang.rabbitmq01.limit;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class Consumer {
public static void main(String[] args) throws Exception {
ConnectionFactory connectionFactory = new ConnectionFactory();
connectionFactory.setHost("192.168.147.146");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
Connection connection = connectionFactory.newConnection();
Channel channel = connection.createChannel();
String exchangeName = "test_qos_exchange";
String queueName = "test_qos_queue";
String routingKey = "qos.#";
channel.exchangeDeclare(exchangeName, "topic", true, false, null);
channel.queueDeclare(queueName, true, false, false, null);
channel.queueBind(queueName, exchangeName, routingKey);
//1 限流方式 第一件事就是 autoAck设置为 false
channel.basicQos(0, 1, false);
channel.basicConsume(queueName, false, new MyConsumer(channel));
}
}
Producer
package com.liwangwang.rabbitmq01.limit;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class Producer {
public static void main(String[] args) throws Exception {
ConnectionFactory connectionFactory = new ConnectionFactory();
connectionFactory.setHost("192.168.147.146");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
Connection connection = connectionFactory.newConnection();
Channel channel = connection.createChannel();
String exchange = "test_qos_exchange";
String routingKey = "qos.save";
String msg = "Hello RabbitMQ QOS Message";
for(int i =0; i<5; i ++){
channel.basicPublish(exchange, routingKey, true, null, msg.getBytes());
}
}
}
consumer控制台消费消息:
消息重回队列
MyConsumer
package com.liwangwang.rabbitmq01.ack;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import java.io.IOException;
public class MyConsumer extends DefaultConsumer {
private Channel channel ;
public MyConsumer(Channel channel) {
super(channel);
this.channel = channel;
}
@Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
System.err.println("-----------consume message----------");
System.err.println("body: " + new String(body));
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
if((Integer)properties.getHeaders().get("num") == 0) {
// 手动签收,重回队列
channel.basicNack(envelope.getDeliveryTag(), false, true);
} else {
channel.basicAck(envelope.getDeliveryTag(), false);
}
}
}
Consumer
package com.liwangwang.rabbitmq01.ack;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class Consumer {
public static void main(String[] args) throws Exception {
ConnectionFactory connectionFactory = new ConnectionFactory();
connectionFactory.setHost("192.168.47.134");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
Connection connection = connectionFactory.newConnection();
Channel channel = connection.createChannel();
String exchangeName = "test_ack_exchange";
String queueName = "test_ack_queue";
String routingKey = "ack.#";
channel.exchangeDeclare(exchangeName, "topic", true, false, null);
channel.queueDeclare(queueName, true, false, false, null);
channel.queueBind(queueName, exchangeName, routingKey);
// 手工签收 必须要关闭 autoAck = false
channel.basicConsume(queueName, false, new MyConsumer(channel));
}
}
Producer
package com.liwangwang.rabbitmq01.ack;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import java.util.HashMap;
import java.util.Map;
public class Producer {
public static void main(String[] args) throws Exception {
ConnectionFactory connectionFactory = new ConnectionFactory();
connectionFactory.setHost("192.168.47.134");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
Connection connection = connectionFactory.newConnection();
Channel channel = connection.createChannel();
String exchange = "test_ack_exchange";
String routingKey = "ack.save";
for(int i =0; i<5; i ++){
Map<String, Object> headers = new HashMap<String, Object>();
headers.put("num", i);
AMQP.BasicProperties properties = new AMQP.BasicProperties.Builder()
.deliveryMode(2)
.contentEncoding("UTF-8")
.headers(headers)
.build();
String msg = "Hello RabbitMQ ACK Message " + i;
channel.basicPublish(exchange, routingKey, true, properties, msg.getBytes());
}
}
}
Consumer:类的重点
Myconsumer的重点:
控制台:
TTL消息
Consumer
package com.liwangwang.rabbitmq01.ttl;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.QueueingConsumer;
import java.util.Map;
public class Consumer {
public static void main(String[] args) throws Exception {
//1 创建一个ConnectionFactory, 并进行配置
ConnectionFactory connectionFactory = new ConnectionFactory();
connectionFactory.setHost("192.168.47.134");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
//2 通过连接工厂创建连接
Connection connection = connectionFactory.newConnection();
//3 通过connection创建一个Channel
Channel channel = connection.createChannel();
//4 声明(创建)一个队列
String queueName = "test001";
channel.queueDeclare(queueName, true, false, false, null);
//5 创建消费者
QueueingConsumer queueingConsumer = new QueueingConsumer(channel);
//6 设置Channel
channel.basicConsume(queueName, true, queueingConsumer);
while(true){
//7 获取消息
QueueingConsumer.Delivery delivery = queueingConsumer.nextDelivery();
String msg = new String(delivery.getBody());
System.err.println("消费端: " + msg);
Map<String, Object> headers = delivery.getProperties().getHeaders();
System.err.println("headers get my1 value: " + headers.get("my1"));
//Envelope envelope = delivery.getEnvelope();
}
}
}
Procuder
package com.liwangwang.rabbitmq01.ttl;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import java.util.HashMap;
import java.util.Map;
public class Procuder {
public static void main(String[] args) throws Exception {
//1 创建一个ConnectionFactory, 并进行配置
ConnectionFactory connectionFactory = new ConnectionFactory();
connectionFactory.setHost("192.168.47.134");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
//2 通过连接工厂创建连接
Connection connection = connectionFactory.newConnection();
//3 通过connection创建一个Channel
Channel channel = connection.createChannel();
Map<String, Object> headers = new HashMap<>();
headers.put("my1", "111");
headers.put("my2", "222");
AMQP.BasicProperties properties = new AMQP.BasicProperties.Builder()
.deliveryMode(2)
.contentEncoding("UTF-8")
.expiration("10000")
.headers(headers)
.build();
//4 通过Channel发送数据
for(int i=0; i < 5; i++){
String msg = "Hello RabbitMQ!";
//1 exchange 2 routingKey
channel.basicPublish("", "test001", properties, msg.getBytes());
}
//5 记得要关闭相关的连接
channel.close();
connection.close();
}
}
在服务者发送消息的时候,就要设置:
控制平台:
2000年以后。。。。
死信队列
MyConsumer
package com.liwangwang.rabbitmq01.dlx;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import java.io.IOException;
public class MyConsumer extends DefaultConsumer {
public MyConsumer(Channel channel) {
super(channel);
}
@Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
System.err.println("-----------consume message----------");
System.err.println("consumerTag: " + consumerTag);
System.err.println("envelope: " + envelope);
System.err.println("properties: " + properties);
System.err.println("body: " + new String(body));
}
}
Consumer
package com.liwangwang.rabbitmq01.dlx;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import java.util.HashMap;
import java.util.Map;
public class Consumer {
public static void main(String[] args) throws Exception {
ConnectionFactory connectionFactory = new ConnectionFactory();
connectionFactory.setHost("192.168.47.134");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
Connection connection = connectionFactory.newConnection();
Channel channel = connection.createChannel();
// 这就是一个普通的交换机 和 队列 以及路由
String exchangeName = "test_dlx_exchange";
String routingKey = "dlx.#";
String queueName = "test_dlx_queue";
channel.exchangeDeclare(exchangeName, "topic", true, false, null);
Map<String, Object> agruments = new HashMap<String, Object>();
agruments.put("x-dead-letter-exchange", "dlx.exchange");
//这个agruments属性,要设置到声明队列上
channel.queueDeclare(queueName, true, false, false, agruments);
channel.queueBind(queueName, exchangeName, routingKey);
//要进行死信队列的声明:
channel.exchangeDeclare("dlx.exchange", "topic", true, false, null);
channel.queueDeclare("dlx.queue", true, false, false, null);
channel.queueBind("dlx.queue", "dlx.exchange", "#");
channel.basicConsume(queueName, true, new MyConsumer(channel));
}
}
Producer
package com.liwangwang.rabbitmq01.dlx;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class Producer {
public static void main(String[] args) throws Exception {
ConnectionFactory connectionFactory = new ConnectionFactory();
connectionFactory.setHost("192.168.47.134");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
Connection connection = connectionFactory.newConnection();
Channel channel = connection.createChannel();
String exchange = "test_dlx_exchange";
String routingKey = "dlx.save";
String msg = "Hello RabbitMQ DLX Message";
for(int i =0; i<1; i ++){
AMQP.BasicProperties properties = new AMQP.BasicProperties.Builder()
.deliveryMode(2)
.contentEncoding("UTF-8")
.expiration("10000")
.build();
channel.basicPublish(exchange, routingKey, true, properties, msg.getBytes());
}
}
}
consumer
Producer重点:
控制台:
后记
enn,就是这样